Shipping containers and plastic lids therefor



Jan. 28, 1969 H ROCHER 40 SHIPPING CONTAINERS AND PLASTIC LIDS THEREFORFiled Feb. 5, 1968 Sheet Jan. 28, 1969 H. ROCHER 3,424,340

SHIPPING CONTAINERS AND PLASTIC LIDS THEREFOR Filed Fezb.) 5, 1968 y ISheet \\\\\\\r//Y .0 1/ v I "A Q j I I w ss //u/ IIIIII Jl k UnitedStates Patent 01 hoe 3,424,340 Patented Jan. 28, 1969 3,424,340 SHIPPINGCONTAINERS AND PLASTIC LIDS THEREFOR Heinz Rocher, Lulsdorf, nearSiegburg, Germany, as-

signor to Inland Steel Company, Chicago, Ill., a corporation of DelawareFiled Feb. 5, 1968, Ser. No. 703,144

Claims priority, application Great Britain, Feb. 10, 1967,

6,582/ 67 US. Cl. 220-55 Int. Cl. B65d 45/32, 53/02; A47j 36/10 19Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Thepresent invention relates to containers and, more particularly, to lidsfor open-head containers of the type commonly used in transportingand/or storing liquid, semi-liquid, pulverized, granular or othersubstances. In its principal aspects, the invention is concerned with animproved lid made of self-supporting plastic material characterized byits resistance to both deformation forces and aggressive substances, andto containers employing such lids, wherein the container and the lid areconstructed so as to mutually cooperate with one another to provide aneffective liquid-tight dust-tight closure assembly under variousconditions of use.

There has been an ever-increasing demand for containers which aresuitable for storing and/or transporting a wide range of different typesof substances including substances which are, or may become, aggressiveto the container itself. Such containers generally have a sidewallformed of a suitable thermoplastic material or of fibrous material.Alternatively, the sidewall may be formed of metal or fiber board andthen internally coated or lined with a thermoplastic material.

It has, however, been found that metallic lids for containers of theforegoing types are undesirable, particularly when the substance to bestored in the container is of such a nature that it can attack the lidor be contaminated thereby. In an effort to solve this problem, it hasbeen proposed that lids made of fiber board or the like be employed; butsuch proposal has not provided an effective solution for the problemsince this type of lid normally is incapable of withstanding the normalrigors of usage. Nor has it been found satisfactory to employ the moreresistant metallic lids in conjunction with thin flexible sheets ofthermoplastic material, the latter serving as a lid liner. Such latterconstructions are disadvantageous in that they normally require the useof separate closure components such as the lid itself and the sheetliner. Moreover, problems are created in acquiring an effective seal forsuch constructions.

Accordingly, it is a general aim of the present invention to overcomethe foregoing disadvantages by providing an improved self-supportingplastic lid which can be removably afiixed to the open end of anopen-head container formed of a wide range of different materials.

It is another object of the invention to provide an improvedself-supporting plastic lid for open-head containers, and containersembodying the same, which are characterized by their simplicity, ease ofassembly, disassembly and reassembly, and which are reliable in use.

A further object of the invention is the provision of containers andself-supporting lids of the foregoing type which are liquid-tight anddust-tight both when completely assembled in tightly closed conditionfor shipment and when only partially assembledfor example, when theconventional clamping ring used to rigidly afiix the lid to thecontainer sidewall is removed. A related object of the invention is theprovision of a plastic lid and open-head container construction whereinthe lid is of unitary construction and wherein the lid effectivelycooperates with the sidewall to form two distinct and circumferentiallycontinuous sealing regions.

Other objects and advantages of the invention will become apparent asthe following description proceeds, taken in conjunction with theaccompanying drawings in which:

FIGURE 1 is a side elevation of an exemplary openhead container herehaving its open end closed by a removable closure assembly in accordancewith the present invention;

FIG. 2 is an enlarged fragmentary cross-sectional view of a containerand plastic lid embodying the features of the present invention, thecontainer being of the type shown in FIG. 1 but here having theconventional expansible and contractable split clamping ring removed,the components being shown in the loosely closed position;

FIG. 3 is a cross-sectional view similar to FIG. 2, but here showing theclamping ring in position with the components in the tightly closedposition;

FIGS. 4 and 5 are cross-sectional views similar to FIG. 3 but depictingmodified forms of plastic lids also embodying the features of thepresent invention; and,

FIG. 6 is a cross-sectional view similar to FIG. 2, but depicting yetanother modified form of plastic lid embodying the present invention.

While the invention is susceptible of various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and will herein be described in detail. Itshould be understood, however, that it is not intended to limit theinvention to the particular forms disclosed, but, on the contrary, theintention is to cover all modifications, equivalents and alternativesfalling within the spirit and scope of the invention as expressed in theappended claims.

Referring now to the drawings, there is shown in FIG. 1 a container,generally indicated at 10, having a sidewall 11 and upper and lowerclosure assemblies generally indicated at 12 and 14 respectively. Asheretofore indicated, the material from which the sidewall 11 is made isnot critical to the present invention, it being understood that thesidewall 11 will either be formed of material that is inert with respectto the substances to be stored in the container, or, alternatively, itwill be internally coated, lined or otherwise treated so as to impartsuch inert characteristic to the sidewall. Thus, the sidewall 11 may beformed of a thermoplastic material, a fibrous material, or even ofsuitable sheet metal. In the latter case, and even in the case offibrous materials, the sidewall may be coated with a thermoplasticmaterial (not shown) or otherwise treated to render it impervious andinert. Alternatively, a separate plastic bag-like liner (not shown) maybe employed in a conventional manner.

For the purpose of permanently closing the lower end of the container10, the lower closure assembly 14 includes a bottom member (not shown)which is rigidly and permanently aflixed to the sidewall 11 by means ofa conventional metallic reinforcing ring 15. The latter is deformedinwardly as indicated at 16 to form an internal rib (not shown) againstwhich the bottom member is seated, with portions of the bottom member,the sidewall 11 and the ring 15 being curled together to form a bottomchime 18.

In order to permit both the loading of substances into the container 10and their subsequent complete or partial removal therefrom, the upperclosure assembly 12 is both removable and replaceable. To this end, theupper end of the sidewall 11 is reinforced by means of a suitablemetallic reinforcing ring 19 which, as best illustrated in FIGS. 2 and3, is curled about the upper extremity 20 of the sidewall, the ring 19and sidewall being formed with an external circumferential groove 21defining a complementary internal circumferential rib 22 adjacent theupper extremity 20 of the container 110. When a lid (not shown in FIG.1, but indicated generally at 24 in FIGS. 2 and 3) is applied to theupper extremity 20 of the container sidewall 11, it can be removably yetfirmly afiixed thereto by any suitable clamping means such, for example,as the conventional expansible and contractable split clamping ring 25shown in FIGS. 1 and 3.

In accordance with one of the important aspects of the presentinvention, the removable lid 24 or cover is of unitary construction andis formed of self-supporting plastic material, the lid having a firstannular skirt which is deformable into the groove 21 in the sidewall 11for fixedly retaining the lid in place during transportation, and asecond annular skirt which is complementary to and cooperates with theinternal rib 22 to form a liquidtight and dust-tight seal. To this end,the plastic lid or cover 24 (FIGS. 2 and 3) is formed of thermoplasticmaterial such as polyethylene. The lid includes a generally flat centralportion 26 surrounded by a channelshaped rim 28. The outer wall of therim 2 8 defines the outermost annular skirt 29, while the inner rim walldefines a concentric inner annular skirt 30.

In keeping with the invention, the second or inner skirt 30 isdimensioned so that when the lid 24 is placed on the container extremity20, the lower-most or free terminal edge 31 of the skirt extends belowthe rib 22, there being an intermediate skirt portion 32 which is shapedcomplementary to the rib. The arrangement is such that the complementaryportion 32 of the inner skirt 30 has a maximum external diameter D1(FIG. 2) which is somewhat greater than the minimum internal diameter D2of the rib 22. Thus, when the lid 24 is placed on the con tainerextremity 20 and a slight downward force is imparted to the lid in anaxial direction, the natural resiliency of the skirt 30 is such that theregion of largest diameter D1 in the skirt portion 32 is deformedradially inwardly, thereby permitting the skirt 30 to snap over the rib22. The skirt 30 then resumes its normal unfiexed state and the rib 22and complementary skirt portion 32 thereafter cooperate (a) to tightlyengage one another so as to retain the lid 24 firmly yet removably inplace and (b) to establish a first circumferential liquid tight anddust-tight seal. Such seal, being in the region of the rib 22,effectively serves to prevent contact between the contents of thecontainer 10 (FIG. 1) and the curled-over portion of the upper metallicreinforcing ring 19. To facilitate assembly of the container body 11 andlid 24, the free edge 31 of the inner skirt 30 flares inwardly, havingan outside diameter D3 less than the internal diameter D2 of the rib.This enables the inwardly flaring portion of the skirt to guide the lid24 into position during assembly.

It will be observed that when the lid 24 and sidewall 11 are in therelative positions shown in FIG. 2, the first or outer annular skirt 29surrounds the curled over portion of the upper reinforcing ring 19, thusdefining a second circumferential liquid-tight and dust-tight seal. Thuseven though the split clamping ring 25 is not yet in place, thecontainer 10 may be safely stored in the condition shown in FIG. 2.

For the purpose of further enhancing the liquid-tight and dust-tightintegrity of the container .10, particularly during transportation butnot necessarily limited to periods of transportation, the lid 24 may befirmly clamped in place by means of the conventional split clamping ring25 shown in FIGS. 1 and 3. In keeping with this aspect of the invention,the outer annular skirt 29 includes a depending portion 34 which extendsbeyond the upper edge of the groove 21. Thus, when the split clampingring 25 is applied and tightened, the skirt portion 34 is bent from theposition shown in FIG. 2 inwardly into the external groove 21 (as shownin FIG. 3) and into intimate surface-to-surface sealing engagement withthe metallic reinforcing ring 19 throughout the entire axial length ofthe skirt 29. This not only serves to increase the sealing area betweenthe skirt 29 and ring 19, and to enhance the seal defined thereby, but,in addition, the lid 24 is now firmly clamped in place on the sidewall11. Consequently, even should the container be dropped when filled,there is virtually no possibility of the lid 24 being disengagedtherefrom.

To further improve the closure and sealing assembly, the free edge ofthe extending portion 34 of the skirt 29 may be formed with a thickenedbead 35. Such bead 35, as best shown in FIG. 3, provides furtherinsurance against the lid 24 slipping from beneath the clamping ring 25and off the container 10.

In carrying out the present invention in accordance with the formthereof illustrated in FIGS. 2 and 3, the substantially flat centralportion 26 of the lid is connected to the inner skirt 30 generally inthe region of the portion 32 of the latter which is complementary to therib 22, as best indicated at 36. This construction is particularlyadvantageous in that it tends both to rigidify the inner skirt 30 and topress the latter firmly into sealing engagement with the rib 22.

Referring next to FIG. 4, a slightly modified lid, generally indicatedat 38, has been shown. The lid 38 is, in most respects, identical to thelid 24 shown in FIGS. 2 and 3. Therefore, identical portions of the lidand of the container are represented by the same reference numerals.However, in this form of the invention it will be observed that the flatcentral portion 26 of the lid 38 is connected to the channel-shaped rim28 at the point, generally indicated at 39, most remote from theinwardly flared free edge 31 of the inner skirt 30. This construction isparticularly advantageous in that the inner skirt 30 retains its maximumnatural resilience, a desirable feature for compensating for possibledeviation in diameter of the rib 22 when the latter is not formed toclose tolerance.

Yet another modified lid construction also embodying the features of theinvention is illustrated in FIG. 5, like portions of the componentsagain being designated by the same reference numerals and unlikeportions being designated by different reference numerals. In thisexemplary construction the lid, generally indicated at 40, includes afiat central portion 26 which is connected to the skirt 30 in the regionof the inwardly tapered free edge 31 of the latter, as best indicated at41. This construction has the advantage that the free edge 31 of theskirt 30 is supported, thus rigidifying the skirt 30 and pressing thelatter firmly into sealing engagement with the rib 22.

To facilitate application of the split clamping ring 25 (shown in FIGS.1 and 3-5), particularly in those instances where the plastic lid isformed of high density thermoplastic material that tends to precludebending thereof, provision may be made for increasing the flexilility ofthe outer annular skirt 29. To accomplish this, and as best illustratedby the lid 42 shown in FIG. 6, a plurality of circumferentially spaced,axially extending slots 44 are formed in the downwardly extendingportion 34 of the outer annular skirt 29, the slots defining a pluralityof lips or tongues 45. The presence of such slits 44 greatly increasesthe flexibility of the skirt portion 34, permitting the tongues 45defining the skirt portion 34 to be bent inwardly upon contraction ofthe expansible and contractable split clamping ring 25.

Those skilled in the art will appreciate that the width of the slits 44and tongues '45 is not critical to the present invention, and may varydependant upon the particular characteristics of the thermoplasticmaterial used to form the lid. Indeed, when the plastic material isrelatively flexible, although self-supporting, such slits may not benecessary. Similarily whether the particular lid construction selectedconforms to that shown in FIGS. 3, 4, or 5 will depend upon suchvariable conditions as the material employed for the lid and/or thesidewall, as well as the dimensions or tolerances of the lid and/orsidewall.

I claim as my invention:

1. A container comprising, in combination, a container sidewall, abottom wall affixed to one end of said sidewall, and a lid removablyaflixed to the other end of said sidewall; said sidewall having anexternal circumferentially disposed groove formed therein adjacent itssaid other end, said groove defining an internal complementarycircumferential rib in said sidewall; said lid being of unitaryconstruction and formed of self-supporting plastic material, said lidhaving a first downwardly extending circumferentially disposed annularskirt dimensioned to extend beyond the upper edge of said groove, saidlid having a second annular skirt disposed concentrically within saidfirst skirt, said second skirt having a free terminal edge extendingbeneath said rib, said second skirt having a portion complementary tothe inner surface of said rib with said portion having a maximumexternal diameter in the region thereof closest to said free edge whichexceeds the minimum internal diameter of said rib whereby said lid isretained firmly yet removably in place by virture of the cooperativeengagement of said rib and said second skirt and the natural resiliencyof the latter, and said lid having a generally fiat central portionjoinetd to an integral with said second skirt.

2. A container as set forth in claim 1 further characterized in thatmeans are porvided for clamping said lid in place upon said container,said clamping means having an annular portion extending into said groovefor bending the portion of said first skirt extending beyond the upperedge of said groove into said groove and clamping said portion of saidfirst skirt tightly against said sidewall.

3. A container as set forth in claim 2 further characterized in thatsaid portion of said first skirt terminates in an annular thickenedbead, said bead being greater in thickness than the space between saidsidewall and said annular portion of said clamping means wherebyinadvertent withdrawal of the bent-over portion of said first skirt isprecluded.

4. A container as set forth in claim 2 further characterized in thatsaid clamping means comprises an expansible and contractablechannel-shaped split ring.

5. A container as set forth in claim 1 further characterized in thatsaid lid is formed of a thermoplastic material.

6. A container as set forth in claim 5 further characterizer in thatsaid material is polyethylene.

7. A container as set forth in claim 1 further characterized in thatsaid fiat central portion of said lid is joined to said second skirt ata point disposed axially outward of the portion of said skirt shapedcomplementary to said rib so as to maximize the resiliency of saidsecond skirt, said second skirt projecting downwardly from said centrallid portion.

8. A container as set forth in claim 1 further-characterized in thatsaid fiat central portion of said lid is joined to said second skirt inthe region defined by the said portion of the latter which iscomplementary to said rib so as to snugly urge said complementaryportion into engagement with said rib.

9. A container as set forth in claim 1 further characterized in thatsaid flat central portion of said lid is joined to said second skirt ata point adjacent the free edge of the latter so as to maximize therigidity of the latter.

10. A container as set forth in claim 1 further characterized in thatthe portion of said first skirt extending beyond the upper edge of saidgroove is axially slitted at circumferentially spaced points so as todecrease resistance to inward bending thereof into said groove.

11. A plastic lid for use with a container of the type having a sidewalland a bottom wall affixed to one end of the sidewall with the sidewallhaving an external circumferentially disposed groove formed thereinadjacent its other end and defining an internal complementarycircumferential rib in the sidewall, said lid characterized in that itis of unitary construction and is formed of selfsupporting plasticmaterial, said lid having a first downwardly extending circumferentiallydisposed annular skirt dimensioned to extend beyond the upper edge ofthe groove, said lid having a second annular skirt disposedconcentrically within said first skirt, said second skirt having a freeterminal edge dimensioned to extend beneath the rib, said second skirthaving a portion complementary to the inner surface of the rib with saidportion having a maximum external diameter in the region thereof closestto said free edge which exceeds the minimum internal diameter of the ribso as to permit said lid to be firmly retained yet removably mounted inplace on the container by virture of cooperative engagement between therib and said second skirt and the natural resiliency of the latter, andsaid lid having a generally flat central portion joined to and integralwith said second skirt.

12. A plastic lid as set forth in claim 11 further characterized in thatsaid first skirt terminates in a thickened annular bead.

13. A plastic lid as set forth in claim 11 further characterized in thatthe free edge of said second skirt flares radially inwardly and is ofsmaller external diameter than the smallest external diameter of theportion of said second skirt which is complementary to the rib.

14. A plastic lid as set forth in claim 11 further characterized in thatsaid lid is formed of thermoplastic material.

15. A plastic lid as set forth in claim 14 further characterized in thatsaid material is polyethylene.

16. A plastic lid as set forth in claim 11 further characterized in thatsaid fiat central portion of said lid is joined to said second skirt ata point disposed axially outward of the portion of said skirt shapedcomplementary to the rib so as to maximize the resiliency of said secondskirt, said second skirt projecting downwardly from said central lidportion.

17. A plastic lid as set forth in claim 11 further characterized in thatsaid flat central portion of said lid is joined to said second skirt inthe region defined by the said portion of the latter which iscomplementary to the rib so as to rigidify the said second skirt.

18. A plastic lid as set forth in claim 11 further characterized in thatsaid flat central portion of said lid is joined to said second skirt ata point adjacent the free edge of the latter so as to maximize therigidity of the latter.

19. A plastic lid as set forth in claim 11 further characterized in thatsaid first skirt has formed therein a plurality of circumferentiallyspaced axially extending slits for reducing resistance of said skirt tobending forces.

References Cited UNITED STATES PATENTS 1/1956 Goodliife et al. 220'55 XR8/1955 Carlson 220 U.S. Cl. X.R. 292256.6

